Variable pitch propeller



Jan. l0, 1933. D. G. LILLEY 1,894,048

. VARI-ABLE FITCH PROPELLER Filed March 18, 1932 4 Sheets-Sheet 1 Jan. 10, 1933. D.YG.L 1L|.EY 1,394,048.

VARIABLE FITCH PROPELLEB @w fr Jan. 10, 1933. D. G. LILLEY 1,894,048

VARIABLE PITcH PROPELLER Filed March 18, 1952 4 sheets-Sheet 3 v f//f 7% if, faz

Jan. 10, 1933. 4 ofc. LILLEY 1,894,048

- VARIABLE FITCH ,PROPELLER Filed March 18, A1952 4 Sheets-Sheet 4 Psa-mad J. io, 1933 'UNITED sTA'rl-:s

PATENT ori-Ica c. LILLEY, or DENVB., comme, Assreivon or ONE-HALF 'ro n.1., omarmt, f or DENVER, coLonAno VARIABLE H TCH rnornminn 'Application filed March 18,1932. Serial No. 599,609.

This invention'relate's to improvements in I mechanisms for use in adjusting a member attached to a rotating shaft while the shaft is rotating and by means of .power obtained from the rotation of the shaft and has refer- -ence more particularly to a mechanism for use in connection with variable pitch propellers for aeroplanes and airships.

It has long been recognized that it is desirv able to change the pitch of an aeroplane or airship propeller so as to adapt the same to conform tothe increased forcesrequired during starting and so as to increase the speed of the aeroplane or airship after it hasv come under headway and many mechanisms have been designed and patented for accomplishing this purpose. x

. n United p States Letters Patent No. 1,712,708, granted to me on 14th day of May, 1929, I have shown, described and tclaimed one mechanism for varying the pitch of propeller blades, while in motion and in my copending application Serial No. 420,402, filed on the 13th day of January, 1930, If have Another object of this invention is to pro-- duce a mechanism that shall be so constructed that it will automatically become inoperative at each limit of variation so as to avoid all danger of breakage during operation.

Another object of this invention is to provide a drive shaft having associated therewith a transmission member that is concentric with the drive shaft and which can be operated in either of two directions with respect tothe drive shaft while the latter is rotating and which shall also carry7 means for limitine' such movement at the end of apredet'ermine adjustment.

' A still further object of this invention is to produce.v a mechanism ofthe class described in which the rotatingiparts shall be locatedA as to limit the strains due t'o centri ugal force andk also to permit the mechanism to be made as compact as possible.

as near to the center of rotation as ossible-so 1 vAnother object of this invention is'to prof vide a pitch varying mechanism with-means to indicate the extent of movement so that the pilot vwill always be' able to' tell exactly at what pitch his propeller is operating.

- A still further object of'this inventionis to produce ahub construction that shall be especially adapted forV use with the transmisl sion mechanism and i-n which the centrifu al force produced by the blades as they revo ve will be resisted by bearings connected with the lblades themselves so as to removel this centrifugal strain from-Q the endfof the drive shaft ,and thereby simplify they construction of the hub and of the blades.

I The above, and other objects that may become apparent as this description proceeds are attained by'means of a construction and an arrangement of parts that will now-be descrlbed in detail, Aand fer this purpose reference will be had tothe accompanying drawl ings in'which the invention has been illustrated in its preferred orm,-and in which:

Fig. 1 is a dametrical section through one end of the crank shaft showing a hydraulic mechanism for operating the independent axial shaft or transmission member;

Fig. 2 is a section taken on line 2-2, Fig. 4,

` and showsl the means employed for moving the member having the two annular friction drive surfaces;

Fig. 3 is asection taken on line 3^`3, Figa/2;

Fig. 4 is a section taken on line 4 4, Fig. l; Fig. 5 is a section taken -on line 5-'-5, Fig. 1,

and shows al part of the indicator;

Fig. 6 is a section taken on line `6-6,'Fig. l, and shows the stator and rotor of the hydraulic motor.;

' Fig. 7 is a diagrammatic .representation showing the relative positions of the motor.

and pump parts and indicating the conduitsthrough wh'ich the liquid flows in passingfrom one to the other;

Fig. 8 is a section taken on line 8'-8, Fig. -l1,` and shows the means employed for conlll) necting the two propeller blades and for securing them to t e drive shaft;

Fi 9 is a detail showing a modified form of ro ler thrust bearing;

Figure 10 is a section taken 0n line 10-10,

Fig. 9; ig. 11 is a front elevation of the parts shown in Fig. 8 looking in the direction of arrow 1 1;

Fig. 12 is a section taken on line 12-12,

Fig. 11;

ig. 13 a view looking in the direction of arms 13 in Fig. 11, arts being broken away to better disclose tie construction;

Fig. 14 is a section similar to that shown in Fig. 1, but showing a mechanical means substituted for the hydraulic means illustrated in Fig. 1; A

Fig. 15 is a section taken on line 15-`i5, Fig. 14, with parts broken away and other parts shown in elevation; and

Fig. 16 is a section'taken on line 1616, Fig. 14.

In the drawings reference numeral 17 designates the wall of the crank casing of an internal combustion engine and reference numeral 18v indicates a portion of the crank shaft,'one crank arm of which has been indicated by reference numeral 19, one end of the crank shaft has a flange 20. This flange is provided with a number of openings 21 spaced equidistantly around its periphery and adaptedto receive bolts for scouring thereto the drive shaft.22.`

The crank casin is preferably provided with an integral orward extension whose bottom wall has` been designated reference numeral 23 and whose front wal has beenv designated by reference numeral 24; the housing of which walls, 23 and 24 form a part, is made of two members divided on a horizontal line as indicated in Fig. 4, the upper part has been designated by reference numerals 23a and 24a, the two parts 23 and 23a are provided with flanges 25 that are perforated for the reception of bolts 26 by means of which they are held in assembled relation. The. upper part of the wall 23a is cut awaj,y as shown in Fig. 4 and the opening thus formed is closed by means of a cover 27 which is held in place by means of bolts 28. Whenthe cover 27 is removed, access can be had to tile interior of the housing. At the place where the two sections 23 and 23al come together a groove 29 has been provided. Located inside of the housing and provided with outwardiy extending projections 30 that fit into the groove 29 is an annular friction drive member 31. Thismember is provided with' two annular inwardly inclined Ysurfaces 32 that are preferably covered with asbestos 33 or some other friction material resembling that l employed for 'automobile brakes. The cylindrical part of member 31 is provided with an $5 opening 34 at its top so that when the cover 27 is removed, access ma be had to the parts located within the me.' ber 31. Y

For the purpose of moving-the annular member- 31, 'a shaft 35 has been provided. This shaft is mounted for rotation in bearings 36 and is provided within'the housing with two s ace cranks 37. The up r ends of the cran s are separated so as to orm two lin ers 3S and the connecting rod 39 has one end, located between the fingers 38 and is pivotally attached to the lat-'zer by means of pivot pins 40. The member 31 is provided with two pairs of ears or lugs 41 between which the other ends of the links 39 VAextend and to which they are pivotally connected by means of pins 42. The outer end of shaft is rovided with a crank 43 to which a rod is pivotally attached. The rod 44 extends to the cabin of the aeroplane and terminates in ya lever located near the pilot seat and by means of which he can rock the shaft 35 about its axis, thereby moving the annular member 31 longitudinally within the housing. The effect of moving member 31 in either direction will be explained as the description proceeds.

Drive shaft 22 is journalled ina bearing 45 formed in the twovertical walls 24 and 24a and has a cylindricai hollow portion located within the housing. The wall of this cylindri-cal portion has been designated b reference numeral 46. rihe inner end of t e cy lindrcal wall is provided with a number of bolts 47 that extend through the cpenin 21 in Bange 20. The outer ends of thesebo are threaded for the reception of the nuts 48. t is evident that when bolts 47 are in place and nuts 48 are tightened, the drive shaft 22 will be firmly secured to the crank shaft 18 so as to form a substantially unita structure. The axis of drive shaft 22 is, o course,

concentric with the axis of the crank shaft 18. The inner surface ofrwall 26 is c lindrical and is formed of several sections o difscribed. Before the construction of the pum and motor are described, attention will be ca led to the fact that 'the drive shaft 22 is provided with an Aaxial opening in which is ocated an Iindependentl movable shaft 53. This shaft extends entire y through the drive shaft 22 and through the cylin rical spa-ce within the wall 46. A gear wheel 54 is secured to the front end of shaft 53. Located within the chamber bounded by .the wall 46 is a motor casing which has been indicated in its entirety by reference numeral 55. This las vthrough which the shaft 53 exten casing is provided with Aan elonted hub 56 and which forms a bearing in which the shaft may rotate. The front surface of member is provided ywith a chamber having two similarly curved is a blade 61 that is biasedvoutwardly by means of a spring 62. It will be seen from Fig.' 6 that when the rotor is turning the blade 'V61 will move inwardly and outwardly so as toalvvays keep in contact with the surface 57.

' The type of rotary pump that has'just been described and which is shown in Flgs.l 6 and 7 is old and well known, and therefore the description will not be gone into in detail,

but only such description will be given as is believed to be necessary to convey a correct understanding of the operation. The rotor 59 is keyed to one end of a cylindrical sleeve 63 that is mounted for rotation on the hub 56. A `cover plate 64 has` a central opening through which the sleeve 63 passes and is provided With a hub 65 with which is operatively y vconnected an annular nut 66 that serves to by means of bolts y the proper thickness to contact with the compress packing material located in the opening 67. The periphery of plate 64 1s securedfto the front side of the pump housing 68. The rotor is made of pump hous-x to reduce to The only parallel opposing surfaces of the ing and the cover plate 68 so .as a minimum any leakage of oil. place vwhere the oil can escape is c member 64 and the sleeve 63 and this is guarded against by means of the packing gland shown. The pump housing is p rovided with a central opening on the rear side thereof, and has secured to it a cover plate 69 that forms one Wall of thev motor housing.

' The motor and the pump are constructed in an identical manner and therefore Ithe parts have been given the same reference numerals. The housing for the motor is completed by member 70 and the four parts, namely, -members 55, 64, 69 and 7() are held 4in assembled relation by means of bolts 68 that extendv entirely through the four parts. Connecting the pump and the motor are condults 1 and 72. These conduits permit the liquid to iiow' in a lmanner which will be hereinafter explained. The cover plate 69 is provided With a hub 73with which is associated an annular nut 74 that serves tocompress packing material located in the space 75, In order to more fully guard against escape of liquid, the front end of sleeve 63'extends a short distance from the front of hub 56 andhas se between the cured to it an annular nut 76 that servesfto compress packing material located V1n the annular opening 77. The housing for Athe` motor is provided with a central bearing 7 8 in which the rear end 79 of shaft 53 is journalled. Secured to the sleeve 63 is a gear wheel 80. This gear is. held against rotation b means of a key 81 and is provided with a rlng 82 of gear teeth whichare in operative enga ement with the pinions 83 that are secure of the friction surfaces 33. By means 'of to the inner ends of the radial shafts 84. These shafts are-journalled in suitable bearings in the Wall 46 and have secured to I ktheir outer ends friction gears 85 whose surfaces are beveled t conform to the inclination shaft 35 the annular member 31 can be moved so as to bring -either of the surfaces 33linto engagement with the friction gears 8,5.

I Let us now assume that the parts so far ldescribed have been assembled as shown and that the crank shaft 18 is rotating. As long as neither of the surfaces 33 come incontact ,with the friction gears 85, the parts secured tothe wall 46 and located within the opening therein, will rotate with the same speed as the crank shaft without moving relative to the latter. If shaft35 is turned so as to bring one of the friction surfaces 33 into Contact with the friction gears 85, the latter will start rotating and through the medium of the pin` ions 83 will rotate the gear 8O and since this is keyed to the sleeve 63 to which the rotor 59 of `the pump is attached, the latter will .begin turning in the pump casing and will force oil through the passages 71 and 72 into the motor and the rotor 59 of the motor will then ystart turning thereupon rotating the shaft 53 relative to the drive sha-ft 22. It is evident that if the member 31 is now moved in the oppositedirection until the other surface 33 comes in contact with the opposite sides of the friction gears 85, the parts will rotate in the opposite direction and thus cause the shaft 53 to rotate in the op osit'e direction with respect to the drive shaft, and

it is therefore evident that it is possible to .move the shaft 53 in either of two directions relative to the drive shaft While the'latter is turning and by means of power" derived from the rotation of the drive shaft.`

Unless some means were provided to limit the extent of the rotation of the shaft 53 in.

either direction, it would continue to turn as long as either one of the friction surfaces 33 were in .contact with the friction gears. When a propeller or other body is to be moved relative to thedrive shaft some means must. be provided forlimiting this movement in` order to prevent breakage or severe strains to develop and for this purpose a. limiting mechanism has been providedv which will now be described.

It will be apparent from an inspection of Figs. 6 and 7 ,that either of the conduits 71 or 72 may conduct the liquid from the pump to the vmotor under pressure, depending upon the direction in which the pump is rotating..

Vhen the parts are operating one of the e011-,A

yduits 71 or 7 will carr liquid under pressure and if a by-pass were obtained so as to return the liquid to the vpump without requir! ing it to pass through the motor, the pump would continue to'operate without ell'ecting rotation ot the motor. For the purpose of by-passing the liquid so as to stop the oper ation of the-motor, each of the conduits 7l and 72 have been connected with a valve mechanism which has been shown most clearly in Fig. 4. These valves are all alike and each consists of a body member 86 that is provided with a central opening 87. This opening is connected by means of a passage 88 to one of the conduits. 'lhe ends of the central opening 87 are normally closed by means of ball checks 89 that are biased towards closed position by means of springs 90and 91. The springs 9() are preferably weaker than the springs 91 for a purpose which will hereinafter appear. When the conduit 72 carries liquid under pressure, the liquid enters the chamber^87 and exerts a force on the balls tending to move them outwardly against their seats and consequently none of the liquids can escape through this valve. If the conduit 72 .becomes the intake to the pump, then thepressure in the same is below atmospheric and any oil contained in the chamber in which the valves are located can pass inwardly lthrough the outer end of the valve mechanism and into the pump. For the purpose of opening the valve when the independent shaft 53 has turned a'predetermined number `of"revolu tions with respect to the drive. shal't, the in- `dependent shaft has been providedA with a worm 92 that is operatively connected with a Worin gear .93. \Vorm gear 923 is n1ounted on a threaded shaft 94 that is journalled in bearings 95. The threaded shaft is provided with a key slot that keepsit from turning in the bearings and therefore when the worin gear 93 is rotated. it will move. the shaft to the right or to the left, depending upon the direction of rotation oi the shaft :'i. The ends of the shafts 94 are provided willi' points that engage the hall 89 oi the vvalve mechanism and serve toI4 move the hall away from the seat and after this has been accomplished.- the oil or otheriluid, insteadof'passing to the motor. flows through the passage 88 and by the hallv89 in the direction indilcated the arrow in Fig. 4 and into the chamber containing the valves.

This oil is then returned to the .pump by passing inwardly through one of the valve mechanisms connected with the intake of the pump as iudicatedby arrow X in Fig. 4. Since the liquid enters the chamber under pressure` it is forced back into the pump and does not ,mechanisms for adjusting 1 tive movement can be had between the drive shaftv and the independent shaft until the member 31 hasbeen shifted so as to bring the other friction surface into engagement with the friction gears 85 and rotate them in opposite direction, whereupon the conduits that formerly contained lliquid under pressurev will become 'the intake conduits for the pump and the' liquid will be assed to the motor through the other con uits whereupon the' motor will rotatein the opposite direction, thereby setting up a movement that tends to move the threaded shafts 94 towards the valves on the' other side and the parts will then continue to function until the valves that are now connected with the pressure conduits, are opened, whereupon the motor will cease to operate.

The means just described, and which is operated by the relative movement between the independent shaft and the drive shaft serves to automatically limit the extent of move ment of the independent shaft relative to the drive shaft as the latter is rotating about its axis. ',lhis limiting means is considered to be of great importance in a mechanism of this type because without some limiting means f of this kind, the parts will be liable to strains that might cause breakage and the operator would be obliged to exercise exceeding care to see that the mechanism was stopped beforesuch strains occurred. I am aware that propeller blades have been provided with mit stops, but as far as I am advised none of them are operated by the' relative movement between the drive shaft and an independent transmission member carried by the drive shaft.

' In order to be able to introduce oil into the chamber containing the valve mechanisnis, the wall 46 has been provided with two or more diametrically located openings 96, and the wall of the pump housing is provided with a corresponding number of open ings correspondingly located and which are normally closed by means of plugs 97. By removing one ot the plugs, oil can be introduced and it is also possible to introduce a tool through these openings forthe purpose of tightening the packing in the packing boxes, if this should become necessary. Sin te there are three packing boxes, I have provided three sets of openings as indicated in Fig. 1, and by introducing a suitable tool through these openings, the packing boxes can be tightened if required. The openings must bc symmetrically located so as not to affect the balance Aof the` parts because they are rotating at a high speed and if an unbalanced condition is present, vibrations will be set up.

lul

i It is desirable, although not absolutely essential, that some indicatin mechanism shall `be provided by means of w ich the pilot can tell at a glance at what pitch his propeller is .operating and for this ,purpose the shaft 53 has been provided with a gear wheel 98 that is inmesh with two vor morege'ars 99. The ears 99 have a threaded conneetionwith `bolts 100 that pass through the wall and are connected at their outer end's to a ring 101.

Gears 99 are held'against movement inwardf ly by means of plates 102. Whenvshaft 53 turns relative to the drivelshaft, the gears 99 will'rotate relative tothe bolts 100 and move the ring 101 in the direction of the axis of the drive shaft. Projecting rearwardly from'the inner surface of the'walls 24a are lugs 103 in which is j ournalled shaft 104. Secured to this shaftare arms 105 that are provided 'at-their free ends with pins 106 that are engaged by the ring 101'.` A spring 107 is provided and so connected with the shaft l 104-and the arms 105'that-it tends to hold.the pins 106 againstl the front (surface of ring f When the mechanism'that has been de` I- scribed above is used for varying the pitch of the propeller blades, the front end of drive shaft 2 2 is provided lwith two radial arms 110. The ends 111 of these radial armsv are bent at right angles as shown in Fig. 8 and are each provided with a semicircularbearing surfaccj112. Bearing caps 113 are secured to the ends 11 by means of bolts 114 and when these are in place, circular bearings-'are `for1ned for holding the `propel er blade assembly which will now be described. The root portions of the lpropeller blades have been indicated by reference numeral 115 and one of these roots portions terminate in a hol-4 low cylindrical part 116. The other propellei blade has a root portion of substantially the same diameter throughout its length and which .is inserted-into the opening in the cylindrical part-116. The inner end of the root portion 115m is thread-cd as indicated at 11'( and secured to thisv threadedportion'is ai hollow member 118 whose outer surfaeeis frustO- conical in shape as' indicated at' 119. Threadl ed t'othe wall of theopening in member y116 is j a ring 120 whose inner surface is tapered to conform to the tapered surface 119. This ring is held in adjusted position by means 'of set screws-121. l The end of ring 120 is provided with teeth 122 and the wall of member 116 hasopenings 123 through which tools may be inserted for the purpose of turning the ring 120 so that it can be adjusted without taking thev assembly apart.- Member 4118 is held y against rotation by means of a key 124. The

outer end of member 118 is tapered slghtl 4and provided with gear teeth 125 with whic 'f 1 a number of pinions.-v 126 cooperate. These pinions are attached to a ring 127 by means of pivot pinsv 128. A cylindrical thrust 'member 129 dias a threaded connection with the inner surface of the opening in member 116.

and its inner end which has been designated by reference nnmeral 130 lis provided with teeththat cooperate-with the pinions in a manner shown in Figs. 9 and 10."` Thepinions 126 take the place of rollers andforma thrust bearing that resists 'the centrifugal strains that are developed when the shaft and the propeller rotates.

Secured to the open end of member 116 is a bearing member 131. The inner surface of this bearing member is tapered and cooperateswith a tapered ring 132 that vis carried by the root ortion 115.'z.- The position of ring 132 is a. justed by means of a threaded ring 133. From the description just given it will be seenthat the two propeller blades whose root portions v'have been indicated by reference numeral 115 areso attached to the drive `shaft .that they oef can rotate in the bearings l112 and also rotate with respect to each other. The centrifugal strains are taken care of by the thrust bearing connection and the overlapping arrangement vof the roots give long bearing surfaces that reduce-the strains to a minimum. Secured to the root portion 115@ is a clamp 134. The

root portion is preferably provided with a threaded section 135 with which threads on the inner surface of the clamping member assembled position by means of bolts 136 in engage. The clamping memberis composed of two parts 134 and 134cvl which are held the manner shown in Fig. 12. 'lhatpart of the clamping member that has been indicated by 134 is provided with a radial arm 13 7 whose outer end is formed by two parts 138 that are separated a shortJ distancel and bc tween which is located a nut 139 that has two j trunnionsk 140 that' are journalled in' bearings provided at the outer endsiof members138 as shownin Fig. 12. Threadedlyconneeted with nuts 139 are threaded rods 141. These rods are tlreaded throughout their entire length and one-half ofthe threaded surface is a right hand thread `and the other half-is a left hand thread in theinanner shown in Fig. 12.- The radial armsA are provided with projections 142 which carry two bearings ,-143 bel tween which is located a nut 144 that h as two oppositely extending trunnions 145 that are journaled in thev bearings 143. The. inner end of the threaded rods 141 extend through the nut 144. Carried bythe threaded rod'141l is a beveled gear 146 that is provided with a spline that engages a keyway 14? in oneside of the threaded rod. One surface of the 'gear 146 is in contact with one end of the nut 144 130 icov this rod are provided with right and leftv hand threads,1the rod`will move simultaneously through the nuts 139 and 144 and will turn the crank arms 137, thereby adjusting the Vpropeller blades. rotarily. There are two of these rods in the man' ner shown in Fig. 12 and the mechanism for operating each is identical and therefore the description above will coverfboth of them. Tt is now necessary, todescribe how the relative rotation ofshafts 22 and 53 will effect rotationy of the propeller .blades about their axes and Yfor this purpose reference will be had moreparticu'larly to Figs. 11, 12 and 13. It has already been described that the front end of shaft 5 3 has a gear wheel 54 and from Fig. 11 it will" be seen that gear'54 is in mesh with two idlers 149 that in turn are in mesh with gears 150. Gears 156 are connected 'by means of shafts 151 to bevelled gears 152 and these in turn are operatively connected with bevel gears 153 secured to one end of the shaft 154. Secured Vto the othenend of the` shaft 154 are bevel gears 155 that .are in mesh with the gear 146. YIt will now be apparent that whenever the gear54 rotates relatively to the drive shaft, it will set in motion the train of gears shown and described and will cause the threaded rods 140Yto rotate about their axes, thereby moving the propeller bladesY rotarily about their comm-on axis. Since 1the crank arms 137 are locatedon op Y site sides of the centers of the propeller b'lad, the correspondingrotagtion of the threaded rod 141 will rotate the propeller blades in .Op

site directions. After an adjustment il); been effected, the parts will be positively held in adjusted position by the tlueaded connec-l tion between the rods 141 and the nuts-139 and 144.. The maximum and minimum pitch is determined by the setting of the threaded shafts 94 which have previously beenderibed so that the pilot can move the pro,- peller biades from f maximum to minimum Ditch and vice versa without necessitating any investigation on his art because these two portions VVare mechanlcally determined. If any intermediateY position is to be used, he can adjust the parts by means ofthe indicator to any intermediate position desired,

The mechanism above described employs a-.hydraulc motor; and a Ypump for effecting relative movement between the drive shaft and the independent shaft. It is not necessary, however, to resort to hydraulic means for-this purpose as substantially the same -re. sultscan be obtained by Vmechanical means and as anexample of such mechanical means, reference will be had to Figs. 14, andv 16, where one is shovlfn. Ingthe embodiment the several in the direction of thelength of the shaft 53.7-110 The parts are-so madeY that the gears 85 will tend to 'move away from the friction surface- Ywith which they are in contact so that iny -order t9 secure l an extended movement of i the partis, member 33 will haveto follow the 115 face of the nut is cylindrical and telescopical- 1y connected withitis the hub`160 of a circular plate 161. A beveled gear 162 is provided with a hub 163 that'has an openingv of the proper size to receive the threaded portion of the shaft.l The shaft has a keyway cut 7,5

therein and thc hub 163 carries a spline 164 that engages in the'keywa and therefore whenever gear162 is rotate it will also ro-Y tate the shaft'53. The two bevelV gears 159 'andi 162 are enclosed in an opeiin in ,a mem#V ber whose cylindrical wall has n designated by 165.' This member has a circular wall that' has an opening through which the hub 163 extends. The plate 1611is secured to themember 165 by means of bolts 166. It 35 will now be seen that the two gears159 and 162 can rotate in the :chamber formed byA held'against relative movement in t e direci tion of the length of theV shaft 53'. Member 9 165 has a radially extending bearing 167 that projects outwardly through an elongated slot 168 in the wall 46. J ournalled in bearing 167 is a shaft 84 to the outenend of which 1s attached a bevel gear 8 5. This bevel gearis 95:-

and '170. These pinions have beens'hown as 100 ,of the same size, but since the itch diameter of gear 159 is less than that o gear 162, its evident that when the shafts 84 are rotated,

the bevelgear 159 will be rotated .faster-than.r`

rotar ymovement with respect to the shaft 5,3, w ich wilicarry the assembly comprising ears and the friction gears movement of the gears 85 until the desired adjustment is effected. This Ymovement of the' parts in the directionof the axiseof ro;v Y

tation constitutes an automatic means for limiting the extent of movement, as by this simple expedient; the parts vwili move only a short distance at each contact between the friction surface 3 and the ear wheel 85 and the pilot must therefore ollow the novement of thief-gear wheels 85 bya corresponding 125 movementgof member 31. i The adjustment of W member 31 is effected by substantially thev same means as-has alread been described which means' comprises t eshaft' 35 and members 165 and 161, but that the will be theorie. indicated by reference numeral 162 105 and therefore nut 157 will `be givenI a relative crank arm 37, the pnly 4difference being thatv 130;

in the construction shown in 14, the links L139 have been omitted so as to save space.

In the embodiment shown in Fig. 14, the indicator has not been'illustrated, but .an in dicator constructed substantially as shown in Fig. 5 can be used with this mechanism, if' o the,independent shaft and drive shaft for desired. f 5

Although this invention has been described in connectionwith a propeller such as that emplo ed with aeroplanes and airships, it ge understood that this is merelyvan exam le and that the mechanism canbe used or adjusting any member relative to a rotating member, while both of them `vare turning about an axis and the mechanism is threfore not limited to propellers, blt can v be used also, for example, in connection with` variable speed belt drives employing V-shaped belts, as well as many other purand t poses. The shaft 18, instead of being a crank shaft can be driven by belts or gears from any suitable prime mover.

Attention is again direct-ed to the fact that; in the bodiments illustrated and-described,

- the drivefshaft has an axial opening through which an independently movable shaft iex-v tends and. means is provided for' turning shaft 53 in either direction relative to the drive shaft while the latter is turning abo`ut its axis and employing for this purpose pow` er derived from the shaft. A

Attention is also directed tothe fact that an aiitomaticall operated means is provided which is cause to function by the relative movement of the drive shaft andthe inde;

rotation of the drive pendent shaft for limiting the movementmf because when the ends of the ribs 30 strike the ends of groove 29, further relative movement becomes impossible in that directionu The construction "shown in Figs. 14 and 15 requires stops for limiting the movement of member 31 because if. no stops were provided nuts 139 might be removed from the bolts 141 o rthe parts might be put under excessive strainsiif the .operator failedtoy lrelease the friction gears at the/proper time.

Having described the invention what is I; 1. Ina devicev of the class specified, in com- 'l bination, a drive shaft mounted for rotation vabout its own axis and povided with an axialI opening, an independent shaft in the axial opening, a member carried by" the drive/ shaft andirotatablet-herewith, but capable of i'ndepe means for moving the independent shaft relative to the drive shaft byrp'owerderived from lthe rotation of the latter, and' means operated by the relative movement between t shaft is moved'relative thereto,

'zov

automatically limiting theextent of'movc-` A ment of the independent'shaft and bod rel'` ative to the drive shaft as the latter Is roabout its axis.

tating A v 2. n a device of the class described, in

combination, a drive shaftmounted for rotation about its own axis, and provided with 'an axial o eninfr an inde endent shaft in.

the axial. opening, a member carried bythe drive shaft designed to he moved with r" spect thereto as' it is rotated therewith, means mterppsed'hetweenthe independent shaft` lsaid member for moving the member with` Aii'espect to the drive shaft Whenever f the independentshaft is caused to move'reL- ative te the drive shaft, means foi-moving the independent shaft relative to the drive shaft, while the latter is turning about'its axis, and means operated by the relative movementbetween the two shafts for limit -ing theextent of the lrelative'movement be' tweerrjftllieiii.

3. Iii combination Withfa variable pitch 'ing an laxial opening, an independent shaft located 1n the axial opemng, a propeller hub and propeller blades carried hy the drive shaft, the blades being designed tobe' robetween the in deprndent shaft and tlpi-'of peller blades for moving them about their f axes `vvlmncver the independent shaft is moved relative tothe drive shaft, means for moving' the independentshaft relative to the drive. shaft, comprising a /hydraulic pump and a hydraulic motor, carried by the tated about axes substantially perpendicular tothe axis of the drive shaft'while'they'lare rotated therewith, meansdrivahly interposed ldrive shaft and rotatable therewith, the independent shaft being drivably `c onnected to `the hydraulic motor, conduits connecting the pump and motor, means for roperating fthe pump by power derived from the rotation of the drive shaft, means comprising the pump Ifor moving the niotor and independent shaft relative to the drive shaftas the latter ro.-

tates about its axis,-meansiperatively connecting the independent sha-ft. with the drrvc shaft forlimiting the extent of movement of the' independent shaft and propeller. blades.

relative to the drive shaft, said means comprising valves secured to the conduits that connect the pump and motor, means inter,-

posed between the valves and the independent shaft for operating th'e valves and'controlling the amount of relative movement iis between the vindependent shaft and drive shaft.

4. In a variable pitch propeller, in combination, a drive shaft mounted for rotation about its axis, lthe drive shaft having an axial opening, an independent shaft located in the axial opening,a propeller hub carried by the drive shaft, propellerblades designed to he rotated about axes perpendicular to the axis of the drive shaft as they are rotated therewith, means drivably interposed between the independent shaft and the blades, so the latter will be moved about their axes whenever the independent shaft is moved relative to the drive shaft, means for moving the independent shaft relative to the drive shaft, comprising a hydraulic pump and motor, and a liquid supply reservoir, all interconnected by conduits, for the transfer of a liquid from one to the other, all carried by the drive shaft and rotatable therewith, the independent shaft being connected to the hydraulic motor, means for operating the pump by power derived from the rotation of the drive shaft, means com rising the pump for moving the motor an independent shaft' relative to the drive shaft as the latter is rotating abut its axis, and means interposed between the pump and motor and controlled by the relative movement of the independent shaft with respect tothe drive shaft, for limiting the extent of movement of the independent shaft with respect to the drive shaft. f i 5. In a mechanism for the purpose specilied, in combination, a drive shaft mounted for rotation about its own axis, ya body carried thereby and movable' with respect thereto, the drive shaft'having an axial opening therein, an independent 'shaft located in the opening and movable with respect to the therein` drive shaft, means for moving the independent shaft relative to thehdrve shaft with power derived from the rotation of the drive shaft andwhile the latter is turning, means for transmitting motion from the independent shaft to the body and for moving the latterin either of two directions relative to the drive shaft while the latteris turning about its axis, and means limiting the relative movement between the drive shaft and the independent shaft.

6. In a mechanism for the pur se specified, in combination, a drive sha mounted for rotation about its own axis, a body carried thereby and movable with respect thereto, the drive shaft having an axial .opening an independent shaft located in the opening and` movable with respect to the drive shaft, means for moving the independent shaft relative to the drive shaft with power derived from the rotation of the drive shaftand while the latter is turning, means for transmitting motion from the independ- 5 ent shaft to the body and for moving the latter in-.either of ,two directions relative to the drive shaft while the latter is turning about its axis, and means also carried by the drive shaft and rotatable therewith for limiting the relative movement between the drive shaft and the inde ndent shaft. v

7. In a variable pitc propeller, in oombination, a drive shaft rmounted for rotation. radial arms carried by the drive shaft, said radial arms havi bearings that are formed in part by remova le caps, the common axis of the bearings beine` substantiall rpendicular to the axis olf the drive sliafite, proeller blades mounted for limitedjrotation in the bearings, the drive shaft having an axial o ning, an independent shaft mounted in t e opening'for movement relative to s aft, motiontransmitting means for` drivably connecting the independent shaft with the propeller blades, means for moving the independent shaft relative to the drive shaft andmeans also carried by the drive shaft and rotatable therewith for limiting the movement of the independent shaft and the propeller blades relative to the drive shaft.'

8. In avariable pitch propeller, in combination, a drive shaft mounted for rotation, radial arms carried by the drive shaft, said radial arms havingbearin ,the common axis of the bearings being su ntiall l'Pen' ldicular to the axis of the drive s ag proller blades mounted for ylimited rotation xn the bearings, the drive shaft' having an I axial opening, an independent shaft mounted in the opening for movement relative to the drive shaft, motion transmitting means for drivably conneetin the indepen nt shaft relative to the drive shaft by power derived from the rotation of the latter and means also carried by the drive shaft and rotatable therewith for limiting the -movement of the independent shaft and the propeller blades relative to the drive shaft.

9. In a variable pitch propeller, in combination, a drive shaft mounted for rotation, said shaft havin an axial opening and provided with radialg'arms rigidly secured there-l to, the radial arms havin bearings, the axes of the bearings bein I su tantially perpendicular to the axis o the drive shaft, a pair the independent shaft f with the pro ller lades, means formo'ving los of pro ller blades journalled in the bearings, t e root portions of the blades ofeach pair being rotatabl connected with each other, means for ho ding the two blades of -each pair against relative movement in the direction of their' length, means for rotati the propeller blades with respect to eac other and with respect to the bearings, mid

means comprising an independent shaft lobearings whenever-the inde dent shaft is moved relative to the drive s aft, means car- Vried b Vthe drive shaft and rotatable therewith or moving the -independent shaft rela-v tive thereto, and means" also carried by the drive shaft and rotatable, therewith for limiting the movement of the independent shaft arlidfhe propeller blades relative to the drive s a 10. In a variable pitch propeller, in combination, a drive shaft mounted for rotation about its own axis, the drive shaft having radial arms secured thereto, so as to rotate therewith, the radial arms being provided with bearings formed partly by means of bearing caps secured to the radial arms, the axes of the bearings so formed being aligned and substantially perpendicular to the axis of the drive shaft, propeller blades mounted in the bearings thus formed, and rotatable about their own axes as they are rotated with the drive shaft, the drive shaft having an axial opening, an inde ndent shaft in the the drive shaft, the said radial shaft having` Ba driving connection with .the independent shaft whereby the independent shaft will be -moved relative to the drive shaft whenever the radial shaft is moved about its axis, means for-rotating the radial shaft about its axis by power derived from the rotation of the drive shaft, and means Acarried by the drive shaft and drivably interposed between the independent shaft and the drive shaft for limiting the movement of theindepend- -ent shaft relative to the drive sliaft so as to prevent movement beyond predetermined limits. i

11. In avariable pitch propeller, in combination, a drive shaft mounted for rotation about its own axis, the drive shaft having radial arms secured thereto, so as to rotate therewith, the radial arms being provided with bearings that are formed partly by means of bearing caps secured to the radial arms, the axis of .the bearings so formed being substantially perpendicular to the axis of the `drive shaft, propeller blades mounted in the bearings for rotation about their own axes', as they are rotated about the axis of the ldrive shaft, the drive shaft having an axial opening, an independent shaft located in the axial opening and drivably connected to the propeller blades by means that will move the blades about their 'own axes when the independent shaft is moved relative to the .thrust bearing member,

drive shaft, means carried by the drive shaft and rotatable therewith for moving the in dependent shaft relative thereto while thel shaft is rotating comprising a hydraulic pum and a hydraulic motor, conduits extendlng between the pump and the motor for v conductin a liquid from one to the other, the motor ing drivably connected to the independent shaft, radial shafts also carried by the drive shaft and rotatable therewith, the radial shafts being mounted for rotation about axes that are perpendicular to the axis of the drive shaft, the radial shafts 'having driving connections with the hydraulic pump, whereby the pump and thehydraulic motor will be simultaneously operated whenever theradial shafts are turned about their axes, limiting means also'carried by the drive ,I

shaft and rotatable therewith, comprising .valves that are connected with the conduits and means interposed between the valves and the .independent Ishaft for operating the valves to limit'the extent of movement of the motor, the independent shaft and the propleller blades relative to the drive shaft as t e' latter is rotating about its axis.

'12. In a variable pitch propeller, in combination, adrive shaft mounted for rotation aboutYJ its own axis, the drive shaft having radial arms secured thereto, so asto rotate therewith, the radial arms being provided with bearings that are formed partly by caps, the axesY means of removable bearin of the bearings so formed bem substantially perpendicular to the axis of t e drive shaft, propeller blades mounted in the bearings for rotation about their own axes, as they are rotated about the axis of the drive shaft,I means for turning the blades about their own axes as they are rotating about the axis of the drive shaft, and means for limiting the extent of movement of the blades relative to thepdrive shaft as the latter is rotating about itsaxis.

13. In a variable pitch propeller, incom bination, a drive shaft mounted for rotation about its own axis, the drive shaft having radial arms secured thereto that are rotatable therewith, the radial arms being provided with bearings whose axes are substantially perpendicular to the axis of thedrive shaft, two propeller blades provided with root portions that overlap each other, one blade being provided with a. cylindrical-like root por.

tion for the reception of another blade root portion of smaller diameter, each blade root portion being provided with an annular nonrotatably secured with respect thereto, a radial bearing located between the two thrust bearing members that are secured to the blade root portions, the cylindrical root portion of the one blade being provided with bearings and bearing supports, oneI formed in the inner end of the cylindrical root portion and one formed in an reception of the root portion'of the blade ot Ythe smaller diameter, the blade root portions being thus journalled'together and *securedf against longitudinal movement with respect to each other, and rotatable with respect to each other about a common axis, are secured Y "combination, a drive shaft mounted for rotain the bearings of the radial arms that are carried by the drive shaft, the bearings of the radial arms being formed partly; by means ot removable bearing caps secured to the radial arms, means for rotating the blades in their bearings: while they are rotated about the axis of the drivel shaft, and means for limiting the extent of movement of the blades relative to the driveishaft as thc latter is rotating about its axis.

14. In afdevice of theclass described, in combination, a drive shaft mounted for rotation about its own axis, a body carried by the drive shaft and rotatable therewith` but which is mounted for movement with respect thereto, a plurality of'power transmission members carried bythe drive shaft, rotatable therewith and mounted for movement with respt thereto, mea-ns for operatively interconnecting the power transmission members and the body so the body will be moved with respect to the drive shaft wheneverthe power transmission members are moved relative to the drive shaft, :means for moving the power transmission membersin the same di- :Jrection and at different speeds with respect to' the drive shaft by power derived from the:

rotation of the drive shaft, thereby producing a differential action between the power transmission members as they are Vmoved Y i 1t 1s rotating therewith, a plurality of power relative to the drive shaft, and means operated by and associated .with the differential movement between the power transmission members for automatically limiting and controlling the movement of the body relative to the drive shaft as the latter is rotating about its axis.

15. In a device of theclass described, in combination, a drive shaft mounted for rotation about# its own axisfa body carried by the drive shaft and rotatable therewitlnbut which is mounted for movement with respect thereto, a plurality of power transmission members carried the drive shaft and rotatable therewith, the transmission members being so mbunted that they may be lmoved with respect to the drive shaft while they are rotated therewith, means for operativelyv interconnecting the power transmission members and the body, so the body will be moved with 'espect to the'drive shaft whenever the power transmission members are moved relative to the drii'fe shaft, power driven means for moving the power transmission members with respect to t'ne drive -shaft, means for simultaneously turning the power transmission members in the same direction and at different speeds and means as- Sociated with and operated the differential movement between the power transmission members for automatically limiting and controlling the movement of the body relative to the drive shaft as thelatter is rotati ing about its vaxis.

1'6. In a device ofthe class described, in

power transmission members relative to the drive shaft as they arerotating therewith, means for operatively interconnecting the powerjra'nsmission members with the body carried by the drive shaft, so the body Ywill be movedY with respect to the drive shaft whenever Ythe power transmission members are movedV with respect thereto, means for creating differential movement between the power transmission members, andmeansassoeited with and operated by the differential action between the power transmission members, for automatically limiting and controlling the movcmelnt'of the body relative to the drive shaft as the latter is rotating about its axis. i

17. In a device of the class described, in combination, i drive shaft mountedfor rota- 100 tion about itsf'own axis, a body carried there- :by and is rotatable therewith` that which is transmission members carried by the drive shaft, and rotatable tlferewithg, said members being mounted for movementV about an axis that is oncentric with the axis of the drive i shaft, means for operatively inter/connecting the power transmission members and the body, sothe body will be moved with respect to the drive'shatt whenever thepnvcr transmission members are moved relative thereto, means for moving the power transmission members relativeto the drive shaft by power derived from the rotation of theidrive shaft, means for moving the power transmission members in the same direction and at different speeds as they are moved relative to the drive shaft, means associated with and operated by the differential movementbetween the power transmission members for automatically iimiting and Vcontrolling the movement of the body relative to the drive shaft as the latter is rotating about its axis.

18. In a device of the class described-in combination, a drive shaft mounted for rotation about its own axis, a body carried by the drive shaft and rotatable therewith, but which is movable with respect thereto as it drive shaft, and mounted for movement with ,respect` to the drive shaft whilerotating therewith, means for operatively connecting the inde endent shaft and the gear wheels with the dy, so the body will be moved with respect to the drive shaft, whenever the independent "shaft and the gear wheels are moved with respect thereto, means carried by the drive shaft and rotatable therewith for moving the independent shaft and the gear wheels with respect to the drive shaft by power derived from the 4rotation of the drive "shaft, means for movingvone of the gear wheels and the independent shaft relative to the other gear Wheel while the vindependent shaft and both gear wheels are moving with respectto the drive shaft, means operated .by the differential action between the gear wheels and the ,relative movement between the gear wheels and the independent shaft for automatically controlling and limiting the extent of movement of the independentshaft and the body relative to the driveshaft as the latter is rotating about its axis.

19. In combination with a variable` pitch propeller, a drive shaft mounted'for rotation.

about its own axis, the drive shaft having an axial opening and radial arms securedk thereto, so as to rotate therewith, theI radial arms4 being'provided with bearings that are partly formed by means of bearing caps, the axes of the bearings4 so formed beingin alignment and substantially perpendicular to the axis of the drive shaft, propeller blades mounted in the bearings so -formedA-for rotation about their own axes as they are rotating with-the drive shaft, means for rotating the blades about theirl axes as they are rotating -with the drive shaft, comprising anw-independent shaft located in the axial opening, the independent shaft being drivably connected to the propeller blades, so the blades will be moved-about their own axeswhenever lthe independent shaft is moved relative' to the drive shaft, means for moving the independentshaft relative to the drive shaft, comprising, two gear wheels carried by the drive shaft and rotatable therewith,-the axes of the gear Wheels being concentric with the common axis of the independent shaft and drive shaft, -the gear wheels being mounted for movement longitudinally ofthe drive shaft as they are rotating therewith, means :operatively connecting ythe gear wheels with the independent shaft, so the independent shaft and the propeller blades will be' moved relative to the drive shaft whenever the gear wheels are moved relative thereto, means carried by the drive shaft and rotatable therewith for moving the gear wheels with respect to the drive shaft by power derived from the rotation of the drive shaft, means for moving the gear wheels relative to each other, and means operated by the relative movement between the gear wheels for automatically controlling the extent of relative movement between them, and for limiting the extent of movement of the independent' shaft' and propeller blades4 relativeto the drive shaft, as the latter is rotating about its axis.

20. In a device of the class described, in c combination, a drive shaft having an\axial opening and mounted for rotation about its own axis, a body carried by the drive shaft and rotatable therewith, said body being movable with respect thereto, means for moving the body with respect to the drive shaft, comprising an independent shaft located in theaxial opening of the drive shaft and rotatable therewith, but adapted to be moved with respect thereto, means for drivably connectingthe body with `the independent shaft,'so the body will be moved relative to the drive shaft, whenever the independent shaft is moved with respect thereto, means for mov- 'ing the independent shaft with respect to the drive shaft,I comprising, two gear wheels ca'rried by the drive shaft and rotatable there- .vith,v said gears each having an operative connection with the independent shaftthe axes of the gear wheels being concentric with the common axis lof the independent shaftand drive shaft, the two gear wheels being adapted to be moved with respect to the drive shaft, while rotating therewithpmeans for rotating the gear wheelsabout their own a'xes,

and relative to the drivel shaft by ower deu rived from the rotation of the drive shaft, said means rotating the two gear wheels in the same direction vand at different speeds whereby relative rotation,` between the two gear wheels is effected as they rtate relative to the drive shaft, and means for limiting the extent of relative movement between the two` gear wheels, and for automatically controlling the movement of the body and the independent shaft relative rt-o the drive shaft, as the latter is rotating about its axis.

21.y In a device of the class described, in combination, a drive shaft mounted for rotation about its own axis,'a body carried thereby and` rotatable therewith, said body being movable with respect thereto, means for moving the body with respect to the drive shaft, comprising a `power transmission member carried by the drive shaftand rotatable therewith, but which can -bemoved with respect thereto, the axis of the power transmission member being concentric with i .to the axis. of the drive shaft,

' the axial opening, two

the airis of the drive shaft, means f or drivably connecting the body with the power transmission member, so'the body will be moved relative to the drive shaft whenever the power transmission ,member -is moved with respect tothe drive shaft, means for moving the lpower transmission member relativey to the drive shaft, comprising two gear wheels that are carried by the drive shaft and rotatable therewith, said ge'ars being operatively connected with the power transmission member, the axes of the` gear wheels being concentric with Ithe commonv axes of the power transmission member and the drive shaft, the two gear wheels being mounted forl rotation relative to the drive shaft as they are rotating therewith, means for rotating the gear wheels abouttheir axes and relative to the drive shaft, by power derived from the rotation of the drive shaft, means .for rotating the two gear wheels in the same direction and relative to each other,

'and means operated by the relative rotationv between the two gearsfor limiting the extent of relative rotation between them, and; for automatically controlling the movement of the body and the power' transmission member relative to. the drive shaft as the latter is rotating about its axis. t

22. In combination with aivariablepitch propeller, va drive shaft mounted for rotation- `about -its ownY axis, the drive shaft an axial'- o ing and radial arms 'sec thereto, an rotatable therewith, the radial arms being provided with bearings that are partly formed by means of bearing caps, the axes of the bearings so formed being in alignment and substantially perpendicular blades mounted forotation in the aringswhile rotating with the drive shaft, means for rotating the blades about their own axis with`the body, so the body willA 'be movedl with respect to the ,drive shaft whenever the independent shaft and the ear wheels are moved relative to the drive s aft, means carried by the drive shaft and rotatable therewith for moving the independent shaft and the gear wheels with respect to the drive shaft by power derived from the rotation of the drive shaft, means for moving'one of the gear wheels and the independent shaft relative to the otherl gear wheel, while the' ropeller enga independent shaft and both gear wheels are moving relative to the drive shaft, and .means operated by the ldifferential action between the gear wheels and between the independent shaft and one, of theggear'wheels or automatically .controllin and limiting the extent of movement of t e independent shaft andthe body relative to the drive shaft, as tlielatter is rotating about its axis.

23. In combination with a variable pitch propeller, a drive shaft mounted for rotation about its own axis, the drive shaft having an axial opening and radial arms secured thereto, so as to rotate therewith, the radial arms being provided with bearings that are formed in part by means of bearing caps, the axes of the bearin s so formed bein `substantially perpendicu ar to the axis of t e drive shaft,

p'opelleriblades mountedl for rotation in the.

arings, means for rotating the blades about their own axis as they are rotating with the drive shaft, comprising an independent shaft located in the axial opening, the independent Parrishaft being drivably connected to ler blades, two gear wheels o rativ y connected to the independent aft, the independent shaft and the two gear wheels having axesthat are concentric. with the axis of the drive shaft, all being carried b the drive 'shaft and rotatable' therewith, an all being respect to the mounted for movement with drive shaft as theyare rotating therewith,

means foi'-b pendent sha Awith the two gear wheels coinprising asplined and threaded portion on the shaft, both of the gear wheels having central openings, one of the gear wheels having a key. secured thereto that fits the spline in the independent shaft, whereb pendent shaft will be rotated a vut its axis whenever the gear wheel is rotated relative to the drive shaft, the other'gear wheel bein provided with threads iii its opening that wi the threaded ortion of the independent s aft, the gear w eels being held a inst movement with respect to eac other ongitudinally of their axes, but both being movable longitudnall lwith respect to the independent s'haftan drive shaft, ower driven means carried bythe drive sha t and rotata- 4ble therewith for moving the gear wheels and 'independent shaft with respect to the drive the. inde- I tively, connecting Athe indeshaft, means for rotating the independent shaft and the gear wheels in the same direction relative to the drive shaft, and in the same direction relative. to each other, said means rotating the independent shaft and one of the gear wheels relative to the other ear wheel as they are rotating in the same direction with respect lto ea'ch other, thereby creating a comparatively slow differential action between the one gear wheel and the independ- 4 ent shaft relative to the othergear wheel, and means for. automatically limiting the extent of movement of the independent shaftand body relative to the drive shaft as the latter is rotating about its axis.

24. In a device of the class described, in combination, a drive shaft mounted for rota- 5 tion about its own axis and provided with an axial opening, a body carried by the drive shaft that is rotatable therewith and adapted to be moved with respect thereto as it is rotating therewith, means for moving the body with respect to the drive shaft, comprising an independent shaft located. in the axial opening, the body being drvably connected with the independent shaft, two gear wheels operatively connected to the independent shaft, the independent shaft and the two gear wheels having axes that are concentric with the axis of the drive shaft, all being carried by the drive shaft and rotatable therewith, and all being mounted for movement with ie spect to the drive shaft as they are rotating therewith, means operatively connecting the independent shaft with the two gear wheels, comprising a splined and threaded portion on the independent shaft, both of the gear wheels having central openings, one of the gear wheels having a key secured thereto that tits the spli-ne in the independent shaft, wheieby the independent shaft will be rotated about its axis whenever the gear wheel is rotated relative to the diive'shaft, the other gear wheelbeing provided with threads in its opening that engage the threaded portion of the independent shaft, the gear wheels being provided with means for holding them 35 against movement with respect to each other `longitudinally of their respective axes, but both gear Wheels being rmovable longitudinally with respeetxto the independent shaft and drive shaft, power driven means carried by the drive shaft, and operated by power derived from the rotation of the drive shaft, for moving the gear wheels and the independent shaft with respect to the drive shaft, means for rotating the independent sha-ft and the gear wheels in the same direction relative 'to the drive. shaft and in the same direction relative to each bisher, means for rotating the independent shaft and one of the gear wheels relative to the other gear wheel as they are rotating in the same direction with respect to each otheigand means for creating a differential action between the independent shaft and the onesgear wheel relative to the otheregear wheel, comprising a radial shaft carried by* the d-riveshaft and rotatable therewith, the radial shaft being mounted for rotation about an axis that is substantially perpendicular to the axis of the drive shaft,

ineansforrotating ,the radial shaft about its ownaxis by power :derived from the rotatienof'the drive shaft, both concentric gear wheels being located on the saine side of the radial shaft, the concentric gears being of diiferentdiameters, Ameans for rotating the gears Lthat are/concentric :withthe drive shaft 'by gears of'suitable diameter secured tothe radial shaft for creating the-desired amount of differential action of .the independent shaft and one of the gear wheels relative to the other gear wheel, and means for automatiindependent shaft and the body'relative to the drive shaft as the latter is rotating about its axis.

25. In a device-of the class described, in combination, a drive shaft mounted for rotation about its own axis, a bearing in which the drive shaft is journaled, the shaft being provided with an axial opening that-extends from one side of the bearing to the other side,

an independent shaft in the axial opening, a-

v cally limiting the extent of movement of the member carried bythe drive shaft designed f to be moved with respect thereto as it is ro tated therewith, means interposed between the independent shaftvand said member for moving the member with respect to the drive shaft whenever the independent shaft is moved relative to theQdrive shaft, power operated means carried by the drive shaft on the opposite side of the bearing from the member and drivably connected to the independent shaft for-moving it relative tothe drive shaft, and means for limiting the ex the root portion of the other blade, which is of such diameter that it can be inserted in the opening, means for journaling the overlapping root portions of the blades together to prevent relative longitudinal movement while permitting the two blades to be rotated relative to each other about a common axis, the blades, with the root portions thus connected being secured in the beai'ings of the radial arms, means for rotating the blades relative toeaeh other while they are rotated about the axisof the drive shaft, and means for limiting the extent of movement of the blades relative to each other and relative to the drive shaft while the latter is rotating about its axis.

27. In a device of the class combination, a drive shaft mounted for rotation about its own axis, a body carried by the drive shaft and rotatable therewith, but which is mounted for movement with respect thereto, a plurality of power transmission gears carried by the drive shaft and rotatable therewith, the transmission gears being so described, in y mounted that they may be moved with respect to the drive shaft while they are rotated therewitlr, means for operatively interconnecting the power transmission gears with the body, so the body will be moved with respect to the drive shaft whenever the power transmission gears are moved relative thereto,l

power driven means,E for moving the power transmission gears with respect to the drive y '3 shaft Yand in the saine direction and relatlve to each other, and means operated by the relative movement between the power transmission gears Yfor limiting the movementof the body relative to the drive shaft as the* latter is rotating about its axis.

Q8. In adcvice of the'class described, in: combination, a drive shaft inolinted for rota- Y tion about its own axis, the drive shaft hav- Y ing an axial opening, a body carried by the drive shaft and rotatable therewith and which is adapted to be movedV with respect thereto, a plurality of power transmission members carriecl by the drive shaft, rotatable therewith and mounted lfor movement about axis that is concentric with: the axis of the drive sh aft, power driven means formoving the power transmission members relative to each other and relative to the'j drive shaft as they are rotating therewith, an independent shaft in the axial opening in the drive sliaf t, said independent shaft forming part of a mechanism for interconnecting the power transmission members and the body for moving the body withjrespect to the drive shaft whenever the power transmission members are moved with respect thereto, and means op-v ed for movement with respect thereto as it is' rotated therewith, means connecting the in dependent shaft with the body, so the body will be moved'relative to the drive shaft whenever the independent shaft is V*moved* with respect thereto, power operated means mounted on the drive shaft between two adjacent drive shaft bearings, anid operatively axis o f the drive shaft as they are rotated therewith, means connecting the independent shalft with the propeller blades, so the blades will be moved about their axes whenever the independent shaftris moved relative to the drive shaft, power operated means located between two adjacent drive shaft bearings, and mounted onY the drive shaft, same'being operatively connected'to the independent shaft for moving the independent shaft'in either direction relative to the drive shaft, and means limiting the Ymovement of the independent shaft relative to the drive shaft as the latter is rotating about its axis.

In testimony whereof I affix my signature.

' DANIEL G. LILLEY. i

connected to the'independent shaft for moving it relative the drive shaft, and means limiting the movement Vof therindependent shaft relative to the drive shaft as the latter is rotating aboutjts axis.Y n

30. In combination with a variable pitch propeller, a drive'shaft niountedrfor rotation in a plurality of bearings, the drive shaft having an axial opening, propeller blades carried by the drive shaft, and mounted for rotation about axes substantially perpendicular to the 

